Download Dane County Friends of Ferals Feline Leukemia Virus (FeLV)

Dane County Friends of Ferals
627 Post Road, Madison, Wisconsin 53713
(608) 467-4067 [email protected]
www.daneferals.org
Feline Leukemia Virus (FeLV ) What is feline leukemia virus?
Feline leukemia virus (FeLV), a retrovirus, so named because of the way it behaves within infected cells. All
retroviruses, including feline immunodeficiency virus (FIV) and human immunodeficiency virus (HIV), produce an
enzyme, reverse transcriptase, which permits them to insert copies of their own genetic material into that of the cells
they have infected. Although related, FeLV and FIV differ in many ways, including their shape, size, and
composition. The specific ways in which they cause disease differ, as well.
How common is the infection?
FeLV-infected cats are found worldwide, but the prevalence of infection varies greatly depending on their age,
health, environment, and lifestyle. In the United States, approximately 2 to 3% of all cats are infected with FeLV.
Rates rise significantly—13% or more—in cats that are ill, very young, or otherwise at high risk of infection.
How is FeLV spread?
Cats persistently infected with FeLV serve as sources of infection. Virus is shed in very high quantities in saliva
and nasal secretions, but also in urine, feces, and milk from infected cats. Cat-to-cat transfer of virus may occur
from a bite wound, during mutual grooming, and (though rarely) through the shared use of litter boxes and feeding
dishes. Transmission can also take place from an infected mother cat to her kittens, either before they are born or
while they are nursing. FeLV doesn't survive long outside a cat's body—probably less than a few hours under
normal household
conditions.
What cats are at greatest risk of infection?
Cats at greatest risk of infection are those that may be exposed to infected cats, either via prolonged close contact or
through bite wounds. Such cats include:
• Cats living with infected cats or with cats of unknown infection status
• Cats allowed outdoors unsupervised, where they may be bitten by an infected cat
• Kittens born to infected mothers
Kittens are much more susceptible to infection than are adult cats, and therefore are at the greatest risk of infection
if exposed. But accompanying their progression to maturity is an increasing resistance to FeLV infection. For
example, the degree of virus exposure sufficient to infect 100% of young kittens will infect only 30% or fewer
adults. Nonetheless, even healthy adult cats can become infected if sufficiently exposed.
What does FeLV do to a cat?
Feline leukemia virus adversely affects the cat's body in many ways. It is the most common cause of cancer in cats,
it may cause various blood disorders, and it may lead to a state of immune deficiency that hinders the cat's ability to
protect itself against other infections. The same bacteria, viruses, protozoa, and fungi that may be found in the
everyday environment—where they usually do not affect healthy animals—can cause severe illness in those with
weakened immune systems. These secondary infections are responsible for many of the diseases associated with
FeLV.
What are the signs of disease caused by FeLV?
During the early stages of infection, it is common for cats to exhibit no signs of disease at all. However, over
time— weeks, months, or even years—the cat's health may progressively deteriorate or be characterized by
recurrent illness interspersed with periods of relative health. Signs can include:
• Loss of appetite
• Slow but progressive weight loss, followed by severe wasting late in the disease process
• Poor coat condition
• Enlarged lymph nodes
• Persistent fever
• Pale gums and other mucus membranes
• Inflammation of the gums (gingivitis) and mouth (stomatitis)
• Infections of the skin, urinary bladder, and upper respiratory tract
• Persistent diarrhea
• Seizures, behavior changes, and other neurological disorders
• A variety of eye conditions
• In unspayed female cats, abortion of kittens or other reproductive failures
How should FeLV-infected cats be managed?
• Confine FeLV-infected cats indoors to reduce their exposure to other infectious agents carried by animals,
and to prevent the spread of infection to other cats in the neighborhood.
• Spay or neuter FeLV-infected cats.
• Feed nutritionally complete and balanced diets.
• Avoid uncooked food, such as raw meat and eggs, and unpasteurized dairy products because the risk of
food-borne bacterial and parasitic infections is much higher in immunosuppressed cats.
• Schedule wellness visits with your veterinarian at least once every six months. Although a detailed physical
examination of all body systems should be performed, your veterinarian should pay special attention to the
health of the gums, eyes, skin, and lymph nodes. A complete blood count, serum biochemical analysis, and a
urine analysis should be performed at every examination. Additionally, your cat's weight should be accurately
measured and recorded, as weight loss if often the first sign of deterioration.
• Closely monitor the health and behavior of your FeLV-infected cat. Alert your veterinarian to any changes
in your cat's health immediately.
• There is no scientific evidence that alternative, immunomodulator, or antiviral medications have any positive
benefits on the health or longevity of healthy infected cats.
How long can I expect my FeLV-infected cat to live?
It is impossible to accurately predict the life expectancy of a cat infected with FeLV. With appropriate care and
under ideal conditions, infected cats can remain in apparent good health for many months to years, although most
succumb to a FeLV-related disease within two or three years after becoming infected. If your cat has already
experienced one or more severe illnesses as a result of FeLV infection, or if persistent fever, weight loss, or cancer
is present, a much shorter survival time can be expected.
Can people become infected with FeLV?
Epidemiological and laboratory studies have failed to provide evidence that FeLV can be transmitted from
infected cats to humans.
Modified from the FeLV brochure produced from the Cornell Feline Health Center. The entire document can be
viewed at http://www.vet.cornell.edu/fhc/resources/brochure/felv.html
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